This paper investigates whether global improvements in human development involve subnational regions in a territorially cohesive way. We use a subnational human development index for 1778 regions within 163 countries over three decades, and propose measures for relative over- and under-performance. We find that frequently observed reductions of within-country inequality are not necessarily accompanied by reductions in under- and over-performance. Moreover, from a global perspective, we detect the presence of a non-negligible set of under-developing subnational regions spanning across 30+ countries that fail to catch-up with the world average human development.